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Title: DIFFUSE EXTRAPLANAR DUST IN NGC 891

We report the detection of vertically extended far-ultraviolet and near-UV emissions in an edge-on spiral galaxy NGC 891, which we interpret as being due to dust-scattered starlight. Three-dimensional radiative transfer models are used to investigate the content of the extraplanar dust that is required to explain the UV emission. The UV halos are well reproduced by a radiative transfer model with two exponential dust disks, one with a scale height of ≈0.2-0.25 kpc and the other with a scale height of ≈1.2-2.0 kpc. The central face-on optical depth of the geometrically thick disk is found to be τ{sub B}{sup thick}≈0.3--0.5 at the B band. The results indicate that the dust mass at |z| > 2 kpc is ≈3%-5% of the total dust mass, which is in good accordance with the recent Herschel submillimeter observation. Our results, together with the recent discovery of the UV halos in other edge-on galaxies, suggest the widespread existence of a geometrically thick dust layer above the galactic plane in spirals.
Authors:
; ;  [1] ;  [2]
  1. Korea Astronomy and Space Science Institute, Daejeon, 305-348 (Korea, Republic of)
  2. Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43606 (United States)
Publication Date:
OSTI Identifier:
22365913
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 785; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC DUST; DETECTION; FAR ULTRAVIOLET RADIATION; GALAXIES; LAYERS; MASS; PHOTON EMISSION; RADIANT HEAT TRANSFER; SCALE HEIGHT; THREE-DIMENSIONAL CALCULATIONS